H-NMR characterization of the human myocardium myoglobin and erythrocyte hemoglobin signals

The 1H-NMR signal of deoxy Mb provides a unique opportunity to measure tissue oxygenation in vivo. To utilize the technique for human application, however, requires a specific spectral characterization of both human Mb and erythrocyte Hb. We report that the proximal histidyl-NH signal of human deoxy Mb resonates at 80.3 ppm at 25 degrees C and maintains a 3.9 ppm separation with the corresponding Hb A signal throughout the physiological temperature range. In the particular case of the human thenar muscle, the deoxy Mb signal is clearly detectable without any interference from Hb.

The development of radial glia and radial dendrites during barrel formation in mouse somatosensory cortex

The development of the mouse barrel field (the mystacial whisker representation in SI cortex) was examined using immunocytochemical probes for radial glia and neuronal dendrites. The maturing dendrites were revealed using antibodies against microtubule-associated protein 2 (MAP2) and the radial glia were demonstrated with a recently described monoclonal antibody, RC2. By postnatal day 7 both antibodies clearly demonstrated a non-uniform distribution of dendrites and glia that was unique to layer IV of the barrel field. Both MAP2-immunoreactive dendrites and RC2-immunoreactive radial glial fibers were dense near the walls (sides and septae) of barrels than near the hollows (centers) of barrels. In contrast, in other cortical regions, radial glia and dendrites did not appear obviously patterned. Not until postnatal day 4 did the pattern of both radial glial fibers and apical dendrites begin to emerge in a barrel-like distribution. We conclude that the non-uniform distribution of radially oriented dendrites and radial glial fibers appears with a similar developmental time course to that described for the appearance of the cellular barrels themselves.

Discs degenerate before facets

The purpose of this study was to determine the relationship between facet joint osteoarthritis and disc degeneration in subjects in whom both MRI and CT scans had been obtained. The MRI scans were used to determine disc degeneration, the CT scans to determine facet joint osteoarthritis. It was hypothesized that disc degeneration would sometimes occur without the presence of facet joint osteoarthritis, but that facet joint osteoarthritis would only occur in the presence of disc degeneration. Sixty-eight sets of scans were included and 330 discs and 390 facet joints were evaluated. There were 144 degenerated discs and 41 levels with facet osteoarthritis. Disc degeneration without facet osteoarthritis was found at 108 levels, while all but one of 41 levels with facet degeneration also had disc degeneration. That one exception occurred in a patient with advanced Paget's disease. Disc degeneration and facet osteoarthritis both were found to increase with increasing age. There was no difference between women and men. Degeneration at the L4-5 and L5-S1 levels was significantly more prevalent than at the L3-4 levels, while degeneration at the L3-4 level was significantly more common than at the L1-2 and L2-3 levels. We conclude that disc degeneration occurs before facet joint osteoarthritis, which may be secondary to mechanical changes in the loading of the facet joints.

Synchronous intrauterine and ectopic pregnancy associated with clomiphene citrate

Although synchronous intrauterine and ectopic pregnancies associated with the use of clomiphene citrate for infertility are rare, the actual incidence might, in fact, be considerably higher than previously thought. The cornerstone for ruling out an extrauterine gestation is the presence of sonographic evidence of an intrauterine pregnancy, as the possibility of concomitant intrauterine and extrauterine gestation is perceived to be statistically rare. This has resulted in an unacceptably high incidence of negative ultrasound interpretations. During a recent 12 month period, four women treated with clomiphene citrate for infertility were diagnosed as having concomitant intrauterine and ectopic pregnancies. Three had pelvic sonograms that were erroneous for the extrauterine component. However, successful evacuation of the products of ectopic gestation was performed in each, despite an immediate preoperative false-negative ultrasound report. Three of the women delivered healthy normal infants at full term, and the fourth woman spontaneously aborted the products of the concomitant intrauterine gestation. All four did well postoperatively, and no gross complications were encountered. Reassessment of ultrasound diagnostic criteria and the use of more sensitive methods, such as endovaginal ultrasound in high risk patients, are indicated for any symptomatic patient using clomiphene citrate for infertility. Awareness of the prevalence of this entity and the limitations of ultrasound will lead to prompt intervention and improved survival rates.

Molecular characterization of HIV-1 isolated from a serum collected in 1976: nucleotide sequence comparison to recent isolates and generation of hybrid HIV

Human immunodeficiency virus type 1 (Z321 designate, HIV-1Z321), the oldest known HIV, was isolated from a serum sample collected in Zaire in 1976 and was molecularly cloned. Restriction enzyme analysis of unintegrated viral DNA revealed the presence of conserved restriction enzyme cleavage sites in the long terminal repeat sequences. Nucleotide sequence analysis of the 3' end of the viral DNA revealed a pattern similar to other HIV-1 isolates described. However, some of the common restriction sites present in other isolates were absent in HIV-1Z321. The extent of differences between HIV-1Z321 and recent isolates from North America and Zaire was 17.86-18.36% on the nucleotide sequence level and 26.5-33.2% difference in the predicted amino acid sequence in the envelope gene. Differences were also noted in 3'-orf (nef: according to HIV gene nomenclature; see Ref. 42) gene and U3 region of the long terminal repeat sequences of HIV-1Z321 and other isolates. Nucleotide sequence of a HIV-1 isolate, 12 years apart from the present isolates, will provide an important time calibration point for the evolutionary divergence of HIV isolates. Hybrid HIV was also generated by transfecting HIV-1Z321 and HIV-1HTLV-III viral DNAs into cells.

Superinfection of a chimpanzee with a second strain of human immunodeficiency virus

Two chimpanzees, one (C-499) infected with the acquired immunodeficiency syndrome-associated retrovirus type 2 (ARV-2) strain of human immunodeficiency virus (HIV) and one (C-560) infected with the lymphadenopathy-associated virus type 1 (LAV-1) strain of HIV, were inoculated with approximately 10(4) tissue culture infective doses of the reciprocal strain. At the time of the second inoculation, both chimpanzees had high titers of HIV-specific antibodies, including antibodies that neutralized both virus strains. After inoculation of the second strain of HIV, the antibody titers in both chimpanzees increased 4- to 10-fold, and in one chimpanzee (C-499), the numbers of infectious peripheral blood mononuclear cells (PBMC) increased 1,000-fold to levels that are comparable with those observed after primary HIV infections. By restriction enzyme analysis of virus recovered from PBMC, both ARV-2 and LAV-1 were identified in C-499, thus demonstrating that superinfection had occurred.

Efficient Tn10 transposition into a DNA insertion hot spot in vivo requires the 5-methyl groups of symmetrically disposed thymines within the hot-spot consensus sequence

Transposon Tn10 inserts preferentially at particular insertion "hot spots" that share a symmetrical 6-base-pair consensus sequence: 5' GCTNAGC 3'. The protein that recognizes this sequence is not known but is likely to be the Tn10-encoded transposase protein. We present evidence that the 5-methyl groups of the two thymines in this sequence are essential for efficient transposon insertion; in their absence the sequence is still recognized, but at lower efficiency. We have reached this conclusion by examination of a specific hot spot whose sequence is 5' GCCAGGC 3'. The innermost cytosines of this sequence happen to be substrates for methylation at their 5 positions by the bacterial dcm-encoded methylase. We find that Tn10 transposes into this site 15 times more frequently in a Dcm+ host than in a Dcm- host; in the Dcm- host, insertions still occur, but at a low frequency. Thus, at this site, the absence of pyrimidine 5-methyl groups at the third positions of the consensus sequence is sufficient to convert a strong insertion hot spot into a weaker but still recognizable hot spot. This observation supports the general proposition, suggested previously by comparisons among consensus sequences, that the presence or absence of these 5-methyl groups is one major feature that can make the difference between a strong and a weak Tn10 insertion hot spot.

Transfusion-associated AIDS: donor-recipient human immunodeficiency virus exhibits genetic heterogeneity

The genetic diversity of the human immunodeficiency virus (HIV) isolated from transfusion-associated AIDS patients has been examined. Restriction enzyme mapping studies of integrated proviral DNA of donor and recipient origin demonstrated genomic variation between isolates. Analysis of the molecularly cloned viral genomes of one donor-recipient pair showed that virus from the recipient had restriction enzyme site differences from the donor, noticeably clustered in the env and orf-2 regions, and also had a greater number of restriction sites in common with the donor as well. These results suggest that HIV may undergo genomic variation in vivo. Comparison of donor-recipient viruses may further the understanding of the molecular basis for AIDS pathogenesis.

Penicillamine-induced exacerbation of rheumatoid arthritis

We have described three patients whose rheumatoid arthritis was exacerbated by penicillamine. The exacerbation was manifested as severe, disabling, febrile, symmetric polysynovitis with normocomplementemia, negative ANA, and reversibility upon discontinuance of the drug. The pathogenesis is yet to be determined.

Alcohol withdrawal and carbamazepine

The use of pharmacologic intervention in the management of alcohol withdrawal syndrome is briefly presented. The use of carbamazepine, a tricyclic anticonvulsant with clinical efficacy in depressive illness, in alcohol withdrawal treatment is reviewed. A comparative analysis between carbamazepine and major drugs used in alcohol withdrawal syndrome is made. This includes the evaluation of both clinical advantages and disadvantages in addition to identification of drug adverse reaction and interaction with alcohol. The mechanism of action of carbamazepine is also examined. Carbamazepine appears to possess a useful pharmacotherapeutic potential in the management of acute alcohol withdrawal syndrome, and its use in long-term treatment is suggested.

Carbamazepine and ethanol elicited responses in rodents

The interaction between carbamazepine, and anticonvulsant with clinical efficacy in alcohol withdrawal syndrome, and ethanol was studied in rodents. Voluntary intake of ethanol by the rat was the behavioral performance test used to assess one aspect of such interaction. Carbamazepine, 50 mg/kg, IP, caused aversion to ethanol drinking. The drug was devoid of action on rat hepatic ethanol and acetaldehyde metabolizing enzymes, i.e., alcohol- and aldehyde dehydrogenase, and on testicular aldehyde dehydrogenase. The moderate induction of the latter by prolonged ethanol consumption was antagonized by a single dose of carbamazepine (50 mg/kg). Administration of carbamazepine, 50 mg/kg twice daily for three consecutive days, moderately inhibited mouse liver alcohol dehydrogenase in the male but not in the female mouse. This treatment did not alter endogenous mouse cardiac lactate dehydrogenase isoenzymes or hepatic aldehyde dehydrogenase in either sex. The enzymatic portion of the study suggests species and sex differences in the effects of carbamazepine studied. The reduction of voluntary drinking of ethanol by carbamazepine may have clinical implications, e.g., the extension of its use in alcohol withdrawal phase to alcohol abstinence.

Recognition of malleus handle fracture in the differential diagnosis of otologic trauma

We have had the opportunity to care for four patients who experienced barotrauma or implosive trauma to their ears. The differential diagnosis in these cases included ossicular injuries as well as possible perilymph fistulae. In each of these cases there was a small conductive hearing loss which fluctuated and a high compliance tympanogram. Careful otoscopy with the aid of pneumomassage revealed an isolated malleus handle (manubrium) fracture. Exploration of one ear was performed to rule out perilymph fistula and the diagnosis of malleus handle fracture was confirmed. Recognition of this injury preoperatively in these three other patients made exploration unnecessary. While injuries to the ossicular chain have been well-described in the literature, isolated malleus handle fracture has not been previously reported.

Auer rods in mature granulocytes: a unique morphologic feature of acute myelogenous leukemia with maturation

The authors observed Auer rods in mature neutrophils, bands, and metamyelocytes in two children with AML with maturation (FAB M2). In order to determine if this rare finding was characteristic of AML M2, the authors reviewed the bone marrows and peripheral blood smears of 50 children with AML M2 and 50 children with other AML subtypes (FAB M1, M3, M4, and M5). They found Auer rods in mature neutrophils and band forms in 10 of 50 patients (20%) with AML M2 but in none of 50 patients with non-M2 AML. This finding was not related to the frequency of mature cells in the specimen or to the frequency of Auer rods in blasts. Cytogenetics did not show a consistent abnormality. The presence of Auer rods in mature granulocytes is unique to FAB M2 AML in the authors' series and supports the concept that in AML at least some of the mature myeloid cells are involved in the leukemic process.

Granular acute lymphoblastic leukemia

Granules in blasts are most typical of acute myeloblastic leukemia. However, there have been scattered reports of patients with acute lymphoblastic leukemia (ALL) that have lymphoblasts with azurophilic cytoplasmic granules. These reports do not describe immunologic markers or cytogenetics. We report five additional cases with detailed cytologic, immunologic, and cytogenetic studies. At diagnosis one of these patients had central nervous system disease, while the others had no unusual features. Four of the five patients attained remission. The blasts of all five patients contained distinct cytoplasmic azurophilic granules. The granules were negative for peroxidase and chloroacetate esterase and positive for PAS, acid phosphatase, alpha-naphthyl acetate esterase incompletely fluoride inhibited, alpha-naphthyl butyrate esterase, and in one case, Sudan black B. In the one patient studied by electron microscopy, characteristic lymphoblasts contained membrane-bound electron lucent inclusions, which stained positively with non-specific esterase. Immunologic markers showed a common ALL phenotype. Different cytogenetic abnormalities were seen in all cases. It is important to recognize the characteristics of this morphologic subtype of ALL in order to avoid a misdiagnosis of acute nonlymphocytic leukemia.

Absence of cardiac arrhythmias during a very-low-calorie diet with high biological quality protein

Fourteen women who were at least 50 lb (22.7 kg) overweight entered the 15 week study which included 4 weeks of 1200 cal (5028 J) balanced diet followed by 7 weeks on a very-low-calorie diet (VLCD) and 4 weeks of refeeding. During the VLCD high biological quality protein (poultry, fish) and recommended supplements of vitamins, minerals and water were used. With the exception of week 5 and 14, 25-h Holter monitorings were done weekly. During the initial 4 weeks, 2 patients showed disturbances of cardiac rhythm and were discharged from the study. Twelve patients completed the trial without any clinically significant changes in cardiac rhythm. The 12 lead ECGs remained normal in all patients throughout the study. The average weight loss was 46 lb (20.9 kg) and the whole program was well tolerated. It is concluded that seven weeks of VLCD with high biological quality protein and recommended supplements appears to be a safe method for weight reduction for severely obese patients.

An evaluation of a ward pharmacy service

An evaluation of a ward pharmacy service showed: 1. Its introduction led to a 40-50% reduction in errors and ambiguities of prescribing. 2. It assisted in the safe and more effective use of medicines in hospitals. 3. Medical staff particularly valued the safety checking applied to their prescriptions and the patient's total medication profile, and the opportunity of seeking information about drugs. Nursing staff most appreciated the checking and clarifying elements which assisted during the administration of drugs, the promotion of the most effective use of medicines and the opportunity of discussing problems of drug therapy.

Ischaemic optic neuropathy--a combined mechanism

A clinical pathological study is reported of a patient who developed bilateral ischaemic optic neuropathy following a massive gastrointestinal haemorrhage with associated vascular complications in watershed areas of the myocardium and brain. Additional factors of giant cell arteritis and diabetic ketoacidosis contributed to the unique pathology. The distribution of infarction to the optic nerve has been related to known studies on the blood supply of the optic nerve.

Recovery following intravenous sedation during dental surgery performed under local anesthesia

Recovery of psychomotor and perceptual performance from two combinations of intravenous sedatives was assessed in 124 oral surgical patients undergoing third molar extractions under local infiltration anesthesia. Ninety-four patients in the experimental group received 15 mg of diazepam and 20 to 200 mg of methohexital intravenously on one occasion and 12.5 mg of diazepam, 20 to 200 mg of methohexital, and 0.1 mg of fentanyl intravenously on another occasion in a randomized, crossover design. Thirty patients in the control group received saline placebo intravenously during a single surgery. Both drug combinations produced significantly prolonged decrements in performance in comparison to placebo. Reduction in the diazepam dose from 15 to 12.5 mg and the addition of fentanyl, a short-acting narcotic, produced greater sedation without prolonging recovery. Psychomotor function recovered to preoperative levels before perceptual performance. These results show that postsurgical deficits in psychomotor and perceptual function result from the sedative drugs and not from the effects of local anesthetics or physiologic and psychological responses to surgery. These results also suggest that psychomotor tests are inappropriate measures of recovery and that superior sedation with rapid recovery may be achieved with reduced doses of longer acting agents such as diazepam and with the addition of shorter acting agents that do not prolong recovery.

A modified lateral projection for anterior and posterior lips of the acetabulum

The standard lateral positions of the acetabulum in injured patients may induce additional trauma. The authors devised a lateral projection which is more comfortable to maintain than the standard views and is potentially less dangerous.

Nitration Studies on 2-Isopropylimidazole

The nitration of 2-isopropylimidazole has been studied under a variety of conditions involving nitration of the unprotonated imidazole, the imidazole anion, or an imidazole radical. From the reaction of nitronium tetrafluoroborate with 1-trimethylsilyl-2-isopropylimidazole there was isolated a dinitro compound the structure of which was shown by X-ray crystallography to be 1,4-dinitro-2-isopropylimidazole.