Morphology of complex lymphoepithelial organs of the anal canal ("anal tonsil") in the bottlenose dolphin, Tursiops truncatus

A complex of lymphoepithelial organs, the "anal tonsils," is a consistent structure in the anal canal of the bottlenose dolphin, Tursiops truncatus. This complex occurs as a circumferential cluster of discrete tonsil-like aggregations of lymphoid tissues, together with epithelial ducts ("crypts") and occasional mucus secretory units in the extreme lower portion of the intestinal tract. These structures are concentrated in the segment lined by stratified squamous epithelium and extend for a variable distance cephalad from the anal aperture. The tonsils appear to be most active, judged by the amount of lymphoid tissue present, in young animals. Depletion of lymphocytes and cystic enlargement of the crypts, probably representing functional as well as morphological involution, is a consistent feature of older animals.

Collection of peripheral-blood diploid cells from chronic myelogenous leukemia patients early in the recovery phase from myelosuppression induced by intensive-dose chemotherapy

PURPOSE

To evaluate whether intensive chemotherapy followed by peripheral stem-cell (PSC) collections during early hematopoietic recovery results in a higher percentage of diploid cell collections in patients with Philadelphia chromosome (Ph)-positive chronic myelogenous leukemia (CML).

PATIENTS AND METHODS

Fifty-five adults with Ph-positive CML received intensive chemotherapy with daunorubicin and high-dose cytarabine (ara-C) (DAUNO-HDAC; 26 patients) or fludarabine, high-dose ara-C, and mitoxantrone (FAM; 29 patients). Collections of the peripheral mononuclear cells were initiated when the WBC count was > or = 0.8 x 10(3)/microL. Simultaneous peripheral and marrow samples were subjected to cytogenetic studies.

RESULTS

Thirty-eight of 55 patients (69%) were able to undergo the PSC collections. The rate of collection was higher in chronic phase (26 of 30 patients; 87%) than in accelerated (11 of 17; 65%) and blastic phases (1 of 8; 12%). Among the 30 patients in chronic phase, cytogenetic analyses of PSC showed cytogenetic responses (Ph-positive < 95%) in 60%, which were major (Ph < 35%) in 43% and complete (Ph = 0%) in 27%. Seven of 19 patients with simultaneous studies (37%; 23% of total) had a significantly lower percentage of Ph-positive cells in the peripheral collection compared with the marrow collection; one had the reverse phenomenon (5%; 3% of total). Cytogenetic responses were modest in both peripheral and marrow collections in CML accelerated and blastic phases. Myelosuppression-associated complications were frequent, resulting in febrile episodes in 76% of patients.

CONCLUSION

PSC collection during early hematopoietic recovery from intensive chemotherapy allowed the collection of diploid-rich stem cells, mostly in chronic-phase CML. The approach could be used for in vivo purging before autologous stem-cell transplantation (ASCT).

Insulin-dependent diabetic microangiopathy in the inner ear

Thickening of the basement membrane in capillaries is implicated in the microangiopathic complications of diabetes mellitus. This study was designed to evaluate microangiopathic changes of the inner ear associated with insulin-dependent diabetes mellitus (IDDM) and concurrent moderate-intensity noise exposure. Male Sprague-Dawley rats were injected with streptozotocin (65 mg/kg) to induce IDDM. Half of the control and diabetic animals were exposed to chronic noise of 95 dB over the 6-month study period. Photomicrographs of the capillaries in the stria vascularis were obtained by transmission electron microscopy, and basement-membrane thickness was measured with an image processing system. This study quantitatively demonstrates basement-membrane thickening consistent with diabetic microangiopathy in the inner ear of IDDM rats. Noise exposure did not significantly change basement-membrane thickness in either diabetic or control animals.

Prolonged survival in chronic myelogenous leukemia after cytogenetic response to interferon-alpha therapy. The Leukemia Service

OBJECTIVE

To determine whether a cytogenetic response after interferon-alpha therapy in patients with chronic myelogenous leukemia is independently associated with improved survival.

DESIGN

Retrospective analysis.

PATIENTS

274 patients with a diagnosis of Philadelphia chromosome-positive chronic myelogenous leukemia in early chronic phase who were treated with interferon-alpha-based programs between 1982 and 1990.

INTERVENTION

Therapy with daily subcutaneous interferon-alpha given at 5 x 10(6) U/m2 body surface area (highest dose schedule allowed on studies) or the maximally tolerated lower-dose schedule.

RESULTS

Overall, 219 (80%) patients achieved a complete hematologic response and 104 (38%) achieved a major cytogenetic response (< 35% Philadelphia chromosome-positive cells). Estimated median survival was 89 months. Several pretreatment factors were associated with failure to achieve a major cytogenetic response and with worse survival. The existing prognostic models were generally predictive of which patients were likely to achieve a major cytogenetic response (P < or = 0.01) and of survival outcomes (P < or = 0.01). Multivariate analysis identified bone marrow basophilia (P < 0.01) and splenomegaly (P < 0.01) as independent poor prognostic factors for survival. Achievement of a major cytogenetic response, entered as a time-dependent variable while accounting for the other independent factors, was associated with improved survival (P < 0.001). Comparison of survival (dated from 12 months into therapy) with cytogenetic response at 12 months showed that a cytogenetic response was associated with longer survival (P < 0.001).

CONCLUSION

Achieving a cytogenetic response with interferon-alpha therapy in patients with chronic myelogenous leukemia was independently associated with improved survival when tested as a time-dependent variable in a multivariate analysis, and this association was confirmed by landmark analysis at 12 months.

Effect of apolipoprotein A-I deficiency on lecithin:cholesterol acyltransferase activation in mouse plasma

Plasma cholesteryl ester (CE) synthesis by lecithin cholesterol acyltransferase (LCAT) is activated by apolipoprotein (apo)A-I. We studied the effect of plasma apoA-I concentration on LCAT activation, using normal, heterozygous or homozygous apoA-I-deficient mice made by gene targeting. Plasma esterified cholesterol concentrations of mice fed chow diets were ordered (mean +/- SEM): 105 +/- 7 (normal) > 70 +/- 5 (heterozygotes) > 26 +/- 2 (homozygotes) mg/dl. Plasma free cholesterol concentrations were similar among the three genotypes. Endogenous LCAT activity, measured as the decrease in plasma free cholesterol after a 1 h incubation at 37 degrees C, was ordered: 44 +/- 3 (normal) > 21 +/- 2 (heterozygotes) > 5 +/- 1 (homozygotes) nmol CE formed/h per ml plasma. Using a recombinant exogenous substrate consisting of egg yolk phospholipid, [14C]cholesterol, and apoA-I, CE formation of normals and heterozygotes was similar (27.4 +/- 0.6 and 28.8 +/- 1.3 nmol/h per ml plasma, respectively), but was significantly less for homozygotes (19.2 +/- 1.7 nmol/h per ml plasma). However, using a small unilamellar vesicle substrate particle containing phospholipid and [14C]cholesterol, CE formation was ordered: 1.6 +/- 0.1 (normal) = 1.6 +/- 0.1 (heterozygotes) > 0.6 +/- 0.1 (homozygotes) nmol/h per ml plasma; addition of apoA-I to the plasma of homozygous animals restored CE formation to normal levels (1.6 +/- 0.1). CE fatty acid analysis demonstrated that plasma from homozygous mice contained significantly more saturated and monounsaturated and fewer polyunsaturated fatty acids compared to normal and heterozygous mice.(ABSTRACT TRUNCATED AT 250 WORDS)

The relationship among stress, depression, locus of control, irrational beliefs, social support, and health in Alzheimer's disease caregivers

This study evaluated the hypothesis that Alzheimer's disease caregivers and control subjects who experienced stressful life events, held the belief that external factors control one's destiny, endorsed irrational beliefs, and had decreased social support would experience more depression and poor health than less stressed individuals who were more internal, had less rigid cognitive beliefs, and had better support. A battery of psychosocial and health measures were administered at baseline and 6 months later. The results suggest that, overall, the experience of marked adversity, increased externality, and the endorsement of irrational beliefs were related to depression and poor health. While diminished social support was not associated with poor health in this study, satisfaction with social support and diminished adherence to irrational beliefs were related to improved ratings of subjective health over time. These findings indicate that psychosocial interventions designed to modify cognitive reactions to stress might improve the quality of life and the physical well being of a population at risk for poor health as a result of their age and life circumstances.

Interleukin-15 and the growth of tumor derived activated T-cells

Interleukin-15 was tested to determine whether this recently discovered cytokine was capable of stimulating the growth of tumor derived activated T cells in culture (TDAC, also referred to as tumor infiltrating lymphocytes). When established cultures of IL-2 induced, IL-2 dependent TDAC were tested, IL-15 stimulated growth in a dose dependent manner, alone or in the presence of IL-2. One established TDAC was cultured with IL-15 alone for 18 passages over a 10 week period. Comparing IL-2 and IL-15 treated cultures, growth rate with IL-15 was slower. IL-15 doubled the secreted interferon alpha and granulocyte-macrophage colony stimulating factor. IL-15 and IL-2 were compared in primary TDAC cultures. IL-15 induced TDAC outgrowth in 3 of 6 cultures. IL-2 induced outgrowth in all 6. Tumor cells were eliminated as TDAC grew out in both IL-2 and IL-15 treated cultures. These results suggested that IL-15 like IL-2, is capable of stimulating the growth of TDAC with antitumor activity, but with certain distinct effects which may be of interest therapeutically.

Cognitive recovery with abstinence and its relationship to family history for alcoholism

OBJECTIVE

The relationship between drinking relapse and family history for alcoholism to cognitive functioning was investigated in alcoholics who completed a 28-day inpatient treatment program.

METHOD

The current study examined 144 primary alcoholics who completed a battery of cognitive tests on admission to treatment and at a 3-4 month follow-up visit. Participants were classified as either family history positive (FH+) (n = 86) or family history negative (FH-) (n = 58) based on information on alcohol dependence in first degree relatives. The subjects were further classified as drinkers (n = 56) or abstainers (n = 88) at follow-up, based upon information gathered about their drinking practices during the interval.

RESULTS

There were no differences between the groups based on family history status at admission to treatment. Comparisons made at follow-up revealed that the abstainers' (both FH+ and FH-) performance improved. The FH+ drinkers' performance was worse than that of both the FH- drinkers and the FH+ abstainers at follow-up. The poor performance of the FH+ drinkers relative to the FH- drinkers was not attributable to differences in drinking consumption during the test-retest interval.

CONCLUSIONS

These results suggest that alcoholics who maintain abstinence following treatment show improvement on cognitive testing at follow-up; both FH+ and FH- abstainers showed improvement, indicating that a positive family history of alcoholism does not impede recovery that occurs with abstinence. The most important finding, however, is that the FH+ drinkers show greater deterioration at follow-up compared to the other groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative antibody responses and protection in mice immunised by oral or parenteral routes with influenza virus subunit antigens in aqueous form or incorporated into ISCOMs

The total and subclass antibody responses of mice and protection of these animals against live influenza A/Sichuan/2/87 virus challenge infection were determined after immunisation with homologous A/Sichuan/87 aqueous or ISCOM-formulated surface glycoprotein subunit antigens administered by either the oral or intramuscular routes. The results show that the greatest systemic and local antibody responses were elicited in mice immunised with A/Sichuan ISCOMs by the intramuscular route; protection against homologous virus challenge was also effective in these animals, particularly after two doses of the vaccine. However, relatively high immune responses and protection were also elicited by the A/Sichuan/87 ISCOM vaccine administered orally. Immunisation of mice by the intramuscular route resulted in levels of serum IgG2a subclass antibody significantly greater than those induced by the same preparation given by the oral route, or by the aqueous A/Sichuan/87 subunit antigen preparation administered by either route. The findings indicate that the ISCOM delivery system can be used for immunisation by the oral route, although in mice, under the conditions used, this strategy compares unfavourably with the intramuscular route in terms of both local and systemic immune responses and protection against homologous challenge virus infection.

Prognostic significance of magnetic resonance imaging in patients with asymptomatic multiple myeloma

PURPOSE

To assess the prognostic significance of magnetic resonance (MR) imaging in patients with newly diagnosed asymptomatic multiple myeloma.

PATIENTS AND METHODS

Thirty-eight consecutive patients with asymptomatic myeloma of low tumor mass and negative skeletal surveys underwent MR imaging of the thoracic and lumbosacral spine. The presence and patterns of marrow involvement were correlated with standard laboratory parameters and time to disease progression.

RESULTS

Nineteen patients (50%) had evidence of marrow involvement at spinal MR imaging. MR patterns of marrow involvement were classified as diffuse (five patients), variegated (nine), and focal (five). Patients with abnormal MR imaging studies required therapy after a median of 16 months, versus 43 months for those with normal MR studies (P < .01).

CONCLUSION

Abnormal marrow patterns were present in half of patients with asymptomatic myeloma. An abnormal MR study of the spine identified asymptomatic patients who were likely to require treatment earlier than those with a normal MR study. A normal MR pattern provided additional justification to defer institution of chemotherapy. However, MR imaging remains an investigational tool to stage patients with multiple myeloma until more data are accumulated.

Artifacts associated with acoustic rhinometric assessment of infants and young children: a model study

The present study was undertaken to determine in model studies whether currently available acoustic rhinometry instrumentation might be used to analyze the nasal cavity configuration of infants and children. A simple nasal cavity model was constructed using eight Lucite inserts that were placed between standard nosepieces provided by the manufacturer and a 35-cm-long polyvinyl chloride pipe closed at its distal end. To simulate the nasal valve, the inserts were 12 mm in length and had apertures ranging in diameter from 2 to 9 mm. A series of experiments was conducted to evaluate the accuracy with which the acoustic rhinometer measured the size of each insert aperture and the configuration of the model system distal to that aperture. Transmission losses caused errors in the area measurement of the insert aperture and the tube distal to the insert. When the insert aperture was < 6 mm in diameter (0.28 cm2), the aperture area was overestimated by > 10%, whereas the area of the distal tube was underestimated by > 10%. As a result of response lags, the acoustic rhinometer also failed to provide an accurate indication of insert length. Finally, oscillation artifacts caused estimates of the distal pipe area to fluctuate. These three systematic errors are described, and their potential impact on acoustic rhinometry in children is discussed.

Partial sleep deprivation reduces natural killer cell activity in humans

Sleep disturbance, measured by either subjective report or electroencephalographic (EEG) assessment of sleep, correlates with a reduction of natural killer (NK) cell activity in major depression. To test whether sleep loss independent of mood disturbance alters daytime values of cellular immune function, the effect of late-night partial sleep deprivation on NK cell activity was studied in 23 medically and psychiatrically healthy male volunteers. After a night of sleep deprivation between 3 and 7 AM, NK cell activity was reduced in 18 of the 23 subjects with average lytic activity reduced significantly (p < .01) to a level 72% of the mean of three separate baseline values. After a night of resumed nocturnal sleep, NK cell activity had returned to baseline levels. These data implicate sleep in the modulation of natural immunity and demonstrate that even modest disturbances of sleep produce a reduction of NK cell activity.

SMS 201-995 in the treatment of refractory prostatic carcinoma

The long-acting synthetic somatostatin analog, SMA 201-995, was used to treat patients with advanced hormonal-refractory prostate cancer. Twenty-two of 24 study patients treated are evaluable for toxicity and 20 are evaluable for response. The dose of SMS 201-995 was 100 mg subcutaneously every 8 hours for 6 weeks. Two patients suffered intolerable gastrointestinal complications requiring early cessation of therapy. No patient had objective evidence of tumor regression. After developing a clinical suspicion that tumor growth accelerated with SMS 201-995, we observed 10 patients closely for 2 months before beginning SMS 201-995 treatment and for the first 2 months on the therapy. In these 10 patients, the serum prostatic acid phosphatase level rose at an accelerated rate after 1 to 2 months of treatment. Among the 20 patients treated and evaluable for response, new osseous metastases developed in 12 and new visceral metastases in 4; 1 developed disseminated intravascular coagulation and 2 developed neurologic complications (mean time to objective progression, 5.6 weeks). Six patients received salvage chemotherapy after disease progressed on SMS 201-995 therapy, 5 of whom have achieved objective tumor regressions. We believe SMS 201995 stimulates prostatic tumor growth and may sensitize tumor cells to subsequent chemotherapy.

Drug use among primary alcoholic veterans

Many people with alcohol dependence use other drugs. However, not much is known about the relationship between their past drug use (not necessarily dependence) and their prognosis following treatment. The goal of this study is first to determine the drug use rates among primary alcoholic men and then to evaluate the possible relationship between past drug use and future alcohol or drug use relapse. As a result, 630 primary alcoholic veterans were recruited from a 28-day inpatient Alcohol and Drug Treatment Program at the San Diego VA Medical Center. Among them, almost two-thirds also had a history of drug use. Subjects were divided into the following four groups which were determined by their lifetime drug use histories: Group I (N = 226) consisted of drug abstainers, Group 2 (N = 142) was made up of alcoholics who had used only marijuana, Group 3 (N = 210) contained stimulant users who had never used opiates, and Group 4 (N = 52) included all opiate users. Comparisons of the four groups at a 3-month follow-up revealed that alcoholic men who had a history of stimulant or opiate use (Groups 3 and 4) were more likely to have had a drug use relapse. However, the four groups had similar alcohol relapse rates.

[N-methylnorleucine-(28,31)]cholecystokinin-(26-33) (SNF 8702) activity at a cloned rat CCKB receptor

[N-methyl-Nle 28,31)]cholecystokinin-(26-33) (SNF 8702) is a highly selective ligand for the CCKB type of receptor present in the vertebrate central nervous system. Radioligand binding data showing that SNF 8702 binding affinity is reduced by the GTP analog guanylyl-imidodiphosphate suggest that SNF 8702 is an agonist but the ability of SNF 8702 to activate CCKB receptors has not been demonstrated. The present study shows that SNF 8702 is a highly potent agonist at rat CCKB receptors expressed on COS-7 cells and that these receptors are coupled to the mobilization of intracellular calcium. The A50 measured for SNF 8702-induced calcium mobilization (66 pM) is over 6-fold less than that of cholecytstokinin octapeptide (420 pM). Data are also presented showing that SNF 8702 has high binding affinity for these receptors with a Kd value (760 pM) consistent with previous measurements using guinea pig brain tissue preparations.

Recovery of eustachian tube function and hearing outcome in patients with cleft palate

Eustachian tube dysfunction is a nearly universal complication of cleft palate, resulting in chronic ear disease and conductive hearing loss. Cleft palate repair is thought to result in recovery of eustachian tube function, but the length of time between repair and recovery of eustachian tube function is not known. Furthermore, the efficacy of tympanostomy tubes in the treatment of eustachian tube dysfunction and hearing sequelae has not been examined in a systematic way. To answer these questions, we performed a retrospective study that used serial audiometric data and tympanometry on 81 patients with cleft palates (162 ears), with follow-up ranging from 1 to 17.3 years. Average time to recovery of eustachian tube function was 6.0 years (range, 1.0 to 10.3 years) after cleft palate surgery. For children followed up for at least 6 years (longest follow-up, 17.3 years), 70% (67 of 85) had normal eustachian tube function at their last follow-up visit. Ears treated with Armstrong tympanostomy tubes required an average of 3.1 tubes per ear until recovery of eustachian tube function, whereas ears treated with Goode T tubes required only 1.1 tubes per ear (p < 0.05). Hearing evaluation revealed that 67% of ears had abnormal hearing thresholds (> 20 dB) before tympanostomy tube placement, whereas only 7.5% of ears demonstrated this loss after tube placement. Furthermore, more than 90% of ears maintained normal thresholds after recovery of eustachian tube function. These data indicate that most children with cleft palates eventually recover normal eustachian tube function after palatoplasty, but for the majority of children, this does not occur for many years.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparative study of criteria for subgrouping alcoholics: the primary/secondary diagnostic scheme versus variations of the type 1/type 2 criteria

OBJECTIVE

This study compared three methods for identifying type 1 and type 2 alcoholism to determine how well the methods agree. It also evaluated the comparability of each of these schemes to the primary/secondary approach to subgrouping alcoholics.

METHOD

Fifty male alcoholic inpatients were given diagnoses of primary alcoholism without antisocial personality disorder or primary antisocial personality disorder with secondary alcoholism on the basis of data from structured interviews. Operationalized criteria for type 1 and type 2 alcoholism from three groups of researchers (Gilligan et al., von Knorring et al., and Sullivan et al.) were also used to designate subgroups of the same subjects.

RESULTS

Subgroups of subjects classified as having type 1 or type 2 alcoholism according to the criteria of von Knorring et al. and of Sullivan et al. showed good levels of agreement, but the criteria of Gilligan et al. yielded poor agreement with those of the other two schemes. Subgroups with type 1 or type 2 alcoholism according to the criteria of Sullivan et al. showed significant overlap with subgroups diagnosed according to the primary/secondary alcoholism scheme: there was 73% concordance between the type 1 subgroup and the subgroup with primary alcoholism and 73% concordance between the type 2 subgroup and the subgroup with primary antisocial personality disorder and secondary alcoholism.

CONCLUSIONS

There is variability in assigning diagnoses of type 1 and type 2 alcoholism with the use of current methods. Also, type 1/type 2 classifications based primarily on age-at-onset factors significantly overlap with the primary/secondary classifications of alcoholics.

Nitric oxide synthase is an active enzyme in the spiral ganglion cells of the rat cochlea

Nitric oxide (NO) mediates the effects of the excitatory amino acids in the central nervous system. Excitatory amino acids, in particular L-glutamate, are thought to be the neurotransmitter(s) present at the cochlear hair cell-afferent nerve synapse. To our knowledge, no studies to date have documented the presence of NO in the cochlea nor attempted to elucidate the role of NO in hearing. Rat cochlea frozen sections were examined for the presence of nitric oxide synthase (NOS) by NADPH diaphorase histochemistry. Vibratome sections of rat cochlea were examined by immunocytochemistry with an antibody to citrulline, an indication of NOS activity. Spiral ganglion cells in the rat cochlea were positive by NADPH diaphorase histochemistry and by anti-citrulline immunocytochemistry. These results indicate that NOS is present and that the enzyme actively produces nitric oxide in the spiral ganglion cells of the rat cochlea. Given our current understanding of neurotransmission in the cochlea, it is reasonable to postulate that the actions of NO in cochlear neuronal tissue are similar to the actions of NO in the CNS and that NO acts as a neurotransmitter/neuromodulator in the cochlea. In addition, because NO has been implicated as a mediator of excitotoxicity in the CNS, NO may play a role in neurotoxicity in the cochlea.

Selective effects of ethanol exposure on metabotropic glutamate receptor and guanine nucleotide stimulated phospholipase C activity in primary cultures of astrocytes

The effects of acute and chronic ethanol exposures on the stimulation of inositol specific phospholipase C by metabotropic glutamate receptor activation were determined in primary cultures of rat cortical astrocytes. Phospholipase C activity was monitored by the formation of [3H]inositol phosphates in the presence of lithium in cells prelabelled with [3H]inositol. Acute exposure to 200 mM ethanol had no significant effect on either basal or L-glutamate stimulated [3H]inositol phosphate formation. In cells chronically exposed to ethanol for 4 days, the [3H]inositol phosphate responses to L-glutamate, quisqualate, and the selective metabotropic receptor agonist, 1S,3R-1-amino-cyclopentane-1,3 dicarboxylic acid (trans-ACPD), were significantly inhibited when compared to control (untreated) cells. In contrast, chronic ethanol exposure had no significant effect on the [3H]inositol phosphate response to endothelin-1, a peptide structurally and functionally unrelated to L-glutamate. Similarly, the stimulation of [3H]inositol phosphate formation by the stable GTP analog, guanine 5'-(gamma-thiotrisphosphate), was also unaffected by chronic ethanol exposure. The results suggest that chronic ethanol exposure does not affect the coupling of GTP binding proteins to phospholipase C, but rather acts in a selective manner to either alter the metabotropic receptor number or to disrupt the normal coupling of this receptor to its GTP binding protein, which may in turn affect receptor affinity.

Effect of hamstring stretching on hamstring muscle performance

The relationship between hamstring flexibility and hamstring muscle performance has not been reported. The purposes of this study were 1) to determine the most effective stretching method for increasing hamstring flexibility and 2) to determine the effects of increasing hamstring flexibility on isokinetic peak torque. Nineteen subjects participated in this study. A two-way analysis of variance was used to compare two stretching techniques: proprioceptive neuromuscular facilitation stretch and static stretch. A one-way repeated measures analysis of variance was used to compare hamstring isokinetic values pre- and poststretching. No significant increase occurred (p < .05) in hamstring flexibility even though increases occurred with each technique: static stretch (+21.3%) and proprioceptive neuromuscular facilitation (+25.7%). Significant increases occurred in peak torque eccentrically at 60 degrees/sec (p < .05, +8.5%) and 120 degrees/sec (p < .05, +13.5%) and concentrically at 120 degrees/sec (p < .05, +11.2%). No significant increase occurred at 60 degrees/sec (p > .05, +2.5%). We concluded that increasing hamstring flexibility was an effective method for increasing hamstring muscle performance at selective isokinetic conditions. Further study is needed to determine if increasing hamstring flexibility will increase performance in closed kinetic chain activities.

Levels of retinoblastoma protein expression in newly diagnosed acute myelogenous leukemia

The relationship between the level of retinoblastoma protein (RB) expression and the survival of 113 newly diagnosed acute myelogenous leukemia (AML) patients was studied. Western blotting was used to determine the level of RB protein present in peripheral blood leukemia cells and results were confirmed in 26 patients by immunohistochemistry. The leukemic cells from 22/113 AML patients (19%) contained RB protein at levels that were equal to or less than the level of RB observed in the mononuclear cell fraction of peripheral blood from normal individuals (Low RB). Levels of RB greater than that of normal blood (Elevated RB) were seen in 91 patients (81%). The median survival of patients with low RB was significantly shorter than that seen in patients with elevated RB, 12 weeks versus 40 weeks (P = .02). Remission induction frequency was 36% in low RB patients compared with 68% in AML patients with elevated RB (P = .01). Multivariate analysis showed that low RB protein level was an independent prognostic factor predictive or poor survival after allowing for other known prognostic factors. These data suggest that a low level of the RB protein at the time of diagnosis is associated with shortened survival in AML patients because of inferior response to conventional therapy. Monitoring of the RB level could identify a subgroup of AML patients with an extremely poor prognosis when treated with chemotherapy alone, who would be eligible for alternative therapeutic strategies.

Combined effects of magnesium deficiency and an atherogenic level of low density lipoprotein on uptake and metabolism of low density lipoprotein by cultured human endothelial cells. I. Biochemical data

The effects of magnesium deficiency on uptake and metabolism of low density lipoprotein (LDL) were investigated using human arterial endothelial cells cultured in media containing various concentrations of magnesium (100-1000 microM) and a high concentration of LDL (2 mg LDL cholesterol/ml) labelled with [3H]cholesteryl linoleate. The LDL uptake was time-dependent and increased for up to 8 h in both the magnesium-deficient and magnesium-sufficient treatments. The extent of LDL uptake progressively increased with the decrease in magnesium concentration of the medium. Surface-bound LDL also increased in a similar manner during the incubation but less extensively than the LDL uptake. The majority of radioactivity from internalized LDL was detected in unesterified cholesterol at all time points in both the magnesium deficiency and sufficiency groups. Only small amounts of radioactivity were found in cholesteryl esters. These findings indicate that most LDL taken up by the cells was rapidly hydrolysed but not readily re-esterified. The lack of re-esterification may be due to a relative deficiency of acyl-CoA:cholesterol acyltransferase (ACAT) and the presence of large amounts of unesterified cholesterol.

Combined effects of magnesium deficiency and an atherogenic level of low density lipoprotein on uptake and metabolism of low density lipoprotein by cultured human endothelial cells. II. Electron microscopic data

The effects of magnesium deficiency on low density lipoprotein (LDL) transport by cultured endothelial cells with a high concentration of LDL (2 mg of LDL cholesterol/ml) were investigated by electron microscopy and by counting the radioactivity of [3H]-LDL transported across an endothelial monolayer grown on culture plate inserts. Electron microscopic examination showed that the number of pits/vesicles in the apical side was time-dependently increased for 24 h in both magnesium-deficient and magnesium-sufficient groups with the exception of 1 h under magnesium sufficiency. The number of pits/vesicles in the basal side was also increased for 8 h in both groups, though there was a decrease at 24 h in the two groups. No difference between either magnesium group at the same time point was statistically significant. [3H]-LDL transport was also time-dependently increased in both magnesium-deficient and magnesium-sufficient groups. In contrast to the results obtained by electron microscopy, the amount of LDL transported under magnesium deficiency was much larger for 24 h than under magnesium sufficiency. Differences in LDL transport between magnesium groups were statistically significant at 4 and 8 h. This finding indicates that magnesium deficiency increases LDL transport across the endothelial monolayer. The increase may be due to energy-dependent movement across endothelial cells, energy-independent movement between cells, or both. However, we conclude that magnesium deficiency increases the energy-dependent LDL transport to some degree since intercellular gap formations were rarely observed in either magnesium group. This LDL transported to the subendothelial space may lead to LDL accumulation and initiate atherosclerosis.

The prognostic importance of blackouts in young men

In order to test the commonly held perception that blackouts are an early diagnostic sign of alcoholism, we evaluated a sample of 230 nonalcoholic young men longitudinally over an 8-12 year follow-up period. Consistent with the literature, blackouts were a common occurrence in this cohort, with 26% of the men reporting blackouts by their early twenties, and 30% of the subjects experiencing blackouts over the approximately 10-year follow-up. Alcohol-related amnestic episodes were associated with the quantity and frequency of drinking, and men with blackouts (especially four or more) were more likely to have other problems related to their heavy drinking. Although few alcoholics will report not having had such amnestic spells, blackouts are not sensitive indicators of the risk for developing alcoholism. The data suggest that blackouts should be viewed as an important warning sign of problem drinking, but not as the "hallmark" of alcoholism.