[Efficacy and safety of pulsed radiofrequency combined with gabapentin in the treatment of acute herpetic neuralgia].

Objective: To explore the clinical efficacy and safety of pulsed radiofrequency (PRF) combined with gabapentin in the treatment of acute herpetic neuralgia (AHN). Methods: A total of 123 AHN patients were retrospectively selected in Henan Provincial People's Hospital from November 2019 to July 2022, who were divided into two groups based on treatment methods: control group (treated with gabapentin, n=61) and study group (treated with gabapentin and PRF, n=62). The visual analog scale (VAS) was utilized for pain severity assessment and the self-rating scale for sleep (SRSS) was utilized for sleep quality evaluation. The differences in serum levels of interleukin (IL)-10, chemokine ligand 10 (CXCL-10), prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), IL-2 and IL-6 before and after treatment were compared between the two groups. The overall treatment effectiveness and the occurrence rates of postherpetic neuralgia and adverse reactions were evaluated in both groups. Results: Among the study group patients, 28 were male and 34 were female, and the age was (62.8±8.5) years. Among the control group patients, 35 were male and 26 were female, and the age was (64.0±7.8) years. The VAS scores of the study group before and after treatment were 7.96±1.33 and 1.52±0.60, respectively, while the control group were 7.68±1.52 and 2.70±0.64. The SRSS scores before and after treatment in the study group were 31.74±5.90 and 12.06±2.81, respectively, while those in the control group were 33.10±5.54 and 14.14±2.96, respectively. Before treatment, there were no statistically differences of the VAS scores and SRSS scores in both groups (all P>0.05). After treatment, the VAS scores and SRSS scores in both groups decreased compared with before treatment (all P<0.05), the study group's VAS scores and SRSS scores were lower than those in the control group (all P<0.05). Before treatment, there were no statistically differences of the serum levels of IL-10, CXCL-10, PGE2, COX-2, IL-2 and IL-6 in both groups (all P>0.05). After treatment, the serum levels of IL-10, CXCL-10, PGE2, COX-2 and IL-6 in both groups decreased compared with before treatment, while the IL-2 level increased. Additionally, the study group had lower serum levels of IL-10, PGE2, COX-2 and IL-6 compared with the control group (all P<0.05). After treatment, the study group had 35 cases of cure, 26 cases of effectiveness, and 1 case of ineffectiveness, while the control group had 22 cases of cure, 31 cases of effectiveness, and 8 cases of ineffectiveness. The overall treatment efficacy of the study group was better than that of the control group (P=0.012). The incidence of postherpetic neuralgia in the study group after treatment was 16.1% (10/62), which was lower than that in the control group, which was 37.7% (23/61) (P<0.05). There were no statistically differences of the occurrence rates of adverse reactions in both groups (all P>0.05). Conclusion: Combining PRF with gabapentin for the treatment of AHN demonstrates better overall efficacy and safety, which can more effectively alleviate pain, improve sleep, and reduce inflammatory cytokine levels.

[Efficacy and safety of high-voltage pulsed radiofrequency combined with pregabalin on severe thoracic postherpetic neuralgia].

Objective: To investigate the efficacy and safety of high-voltage pulse radiofrequency combined with pregabalin on severe thoracic postherpetic neuralgia (PHN). Methods: A total of 103 patients with PHN who were admitted to the Department of Pain Medicine of Henan Provincial People's Hospital from May 2020 to May 2022 were retrospectively selected, including 50 males and 53 females, and aged 40 to 79 (65.4±9.2) years. The patients were divided into two groups according to the treatment methods they received: the control group (n=51) and the study group (n=52). The patients in the control group were treated with oral pregabalin, and the patients in the study group received pregabalin plus high-voltage pulse radiofrequency therapy. The pain intensity and efficacy of the two groups were evaluated before treatment and 4 weeks after treatment. The pain intensity, the sleep quality and the efficacy of treatment was evaluated by visual analogue scale (VAS) score, Pittsburgh Sleep Quality Index (PSQI) score and nimodipine method, respectively. The levels of pain mediators including serum neuropeptide Y (NPY), prostaglandin E2 (PGE2), substance P (SP) and ß-endorphin were measured. The differences of the above indicators and the incidence of adverse reactions were compared between the two groups. Results: The VAS scores of the study group and the control group before treatment were 7.94±0.76 and 8.20±0.81, and PSQI scores were 16.84±3.90 and 16.29±3.84, respectively, with no statistically significant differences (both P>0.05). After 4 weeks of treatment, the VAS scores of the two groups were 2.84±0.80 and 3.35±0.87, and PSQI scores were 6.78±1.90 and 7.98±2.40, respectively, and the VAS score and PSQI score in the study group were lower than those in the control group (both P<0.05). There were no significant differences of the serum levels of NPY, PGE2, SP and ß-endorphin before treatment in the study group and control group (all P>0.05). After 4 weeks of treatment, the levels of NPY, PGE2, SP and ß-Endorphin in the study group were (240.7±26.8) ng/L, (74.4±8.6) µg/L, (108.9±15.7) ng/L and (4.4±0.9) ng/L, which were lower than those in the control group [(268.1±29.4) ng/L, (79.7±8.3) µg/L, (115.2±16.2) ng/L, (5.2±1.3) ng/L, respectively], with statistically significant differences (all P<0.05). After treatment, 29 cases were cured, 16 cases were markedly effective and 6 cases were effective in the study group, while 16 cases, 24 cases and 8 cases were cured, markedly effective and effective in the control group, respectively. The overall efficacy of patients in the study group was better than that in the control group (Z=-2.32, P=0.018). The incidence of adverse reactions in the study group and control group was 11.5% (6/52) and 7.8% (4/51), respectively, with no statistically significant difference (χ2=0.40, P=0.527). Conclusion: High-voltage pulse radiofrequency combined with pregabalin can significantly improve the pain intensity and sleep quality of patients with severe thoracic PHN and reduce the levels of pain mediators, with a high safety profile.

[Efficacy and safety of high-voltage pulsed radiofrequency combined with pregabalin on severe thoracic postherpetic neuralgia].

Objective: To investigate the efficacy and safety of high-voltage pulse radiofrequency combined with pregabalin on severe thoracic postherpetic neuralgia (PHN). Methods: A total of 103 patients with PHN who were admitted to the Department of Pain Medicine of Henan Provincial People's Hospital from May 2020 to May 2022 were retrospectively selected, including 50 males and 53 females, and aged 40 to 79 (65.4±9.2) years. The patients were divided into two groups according to the treatment methods they received: the control group (n=51) and the study group (n=52). The patients in the control group were treated with oral pregabalin, and the patients in the study group received pregabalin plus high-voltage pulse radiofrequency therapy. The pain intensity and efficacy of the two groups were evaluated before treatment and 4 weeks after treatment. The pain intensity, the sleep quality and the efficacy of treatment was evaluated by visual analogue scale (VAS) score, Pittsburgh Sleep Quality Index (PSQI) score and nimodipine method, respectively. The levels of pain factors including serum neuropeptide Y (NPY), prostaglandin E2 (PGE2), substance P (SP) and ß-Endorphin were measured. The differences of the above indicators and the incidence of adverse reactions were compared between the two groups. Results: The VAS scores and PSQI scores of the study group and the control group before treatment were (7.94±0.76), (8.20±0.81), (16.84±3.90) and (16.29±3.84), respectively, with no statistically significant difference (both P>0.05). After 4 weeks of treatment, the VAS scores and PSQI scores of the two groups were (2.84±0.80), (3.35±0.87), (6.78±1.90) and (7.98±2.40), respectively, and the VAS score and PSQI score in the study group were lower than those in the control group (both P<0.05). Serum levels of NPY, PGE2, SP and ß-Endorphin were (298.5±31.0) ng/L, (92.3±11.0) µg/L, (156.8±21.4) ng/L, and (8.6±1.6) ng/L in the study group and (304.2±28.6) ng/L, (94.4±12.9) µg/L, (152.7±23.8) ng/L and (8.2±1.8) ng/L in the control group, with no significant differences (all P>0.05). After 4 weeks of treatment, levels of NPY, PGE2, SP and ß-Endorphin were (240.7±26.8) ng/L, (74.4±8.6) µg/L, (108.9±15.7) ng/L and (4.4±0.9) ng/L, which were lower than those in the control group [(268.1±29.4) ng/L, (79.7±8.3) µg/L, (115.2±16.2) ng/L, (5.2±1.3) ng/L, respectively], with statistically significant differences (all P<0.05). After treatment, 29 cases were cured, 16 cases were markedly effective and 6 cases were effective in the study group, while 16 cases, 24 cases and 8 cases were cured, markedly effective and effective in the control group. The overall efficacy of patients in the study group was better than that in the control group (Z=-2.32, P=0.018). The incidence of adverse reactions in the study group and control group was 11.5% (6/52) and 7.8% (4/51), respectively, with no statistically significant difference (χ2=0.40, P=0.527). Conclusion: High-voltage pulse radiofrequency combined with pregabalin can significantly improve the pain and sleep quality of patients with severe thoracic PHN and reduce the level of pain factors, with a high safety profile.

Linoleic acid and α-linolenic acid inhibit conjugative transfer of an IncX4 plasmid carrying mcr-1.

AIMS: The aim of this study was to determine the effects of unsaturated fatty acids on clinical plasmids. METHODS AND RESULTS: Two unsaturated fatty acids, linoleic acid (LA) and α-linolenic acid (ALA) at final concentration 0, 0·03, 0·3 and 3 mmol l-1 , respectively, were used to assess the effects on conjugative transfer of a mcr-1-harbouring plasmid pCSZ4 (IncX4) in conjugation experiment. The inhibitory mechanisms were analysed by molecular docking and the gene expression of virB11 was quantitated by qRT-PCR. Target plasmid diversity was carried out by TrwD/VirB11 homology protein sequence prediction analysis. Our results showed that LA and ALA inhibit plasmid pCSZ4 transfer by binding to the amino acid residues (Phe124 and Thr125) of VirB11 with dose-dependent effects. The expression levels of virB11 gene were also significantly inhibited by LA and ALA treatment. Protein homology analysis revealed a wide distribution of TrwD/VirB11-like genes among over 37 classes of plasmids originated from both Gram-negative and Gram-positive bacteria. CONCLUSIONS: This study demonstrates representing a diversity of plasmids that may be potentially inhibited by unsaturated fatty acids. SIGNIFICANCE AND IMPACT OF THE STUDY: Our work reported here provides additional support for application of curbing the spread of multiple plasmids by unsaturated fatty acids.

[The correlation study on pathogenesis of B cell activation factor in eosinophils and neutrophil- predominant chronic rhinosinusitis with nasal polyps].

Chronic rhinosinusitis with nasal polyps (CRSwNP) is one of the common diseases. Involving the nasal passages and nasal passages, it may affect 10% of the global population. Surgical intervention is usually required. Its pathogenesis is a multielement and multistep complex process. Current multi-factor hypothesisplays a dominant role in the etiology of nasal polyps (NP). Infectious factors always play an important role in the pathogenesis of CRSwNP. The lesions of nasal polyp have different inflammatory cell infiltration and can be divided into two types in immunophenotpe: the first is characterized by Th2 cell reaction and marked eosinophil infiltration,and the second is Th1/Th17 cell response and non-eosinophil infiltration are characteristic.NP, which is mainly infiltrated by neutrophils, is more and more common in China. B cell activation factor (BAFF) is a major inflammatory factor related to the regulation of B cell activation.Recent experiments have shown that BAFF is also high in nasal polyps.In this paper, the effects and interactions of BAFF and eosinophils and neutrophils in CRSwNP were reviewed.

Development of a new reaction system for the synthesis of highly optically active alpha,gamma-substituted gamma-butyrolactones.

A highly useful method for the synthesis of optically active alpha,gamma-substituted gamma-butyrolactones has been developed. The SmI(2)-induced reductive coupling of chiral 2-alkyl acrylates derived from isosorbide with ketones in the presence of (1S)-(-)-2,10-camphorsultam as a proton source give the chiral alpha,gamma-substituted gamma-butyrolactones in good yields and high enantiomeric purities (up to >99% ee for trans and 75% ee for cis). The reaction system has been investigated with various ketones, and it is demonstrated that this system is very effective for trans-alpha,gamma-substituted gamma-butyrolactones. Both the chiral auxiliary and the hindered proton source in this system are necessary for the observed excellent ee values of the products. The absolute configuration of the trans products is assigned on the basis of the X-ray crystal structure.

Base-catalyzed epimerization of the butenolide in annonaceous acetogenins.

The elusive epimerization process in the chiral butenolide moiety of Annonaceous acetogenins was examined under several sets of conditions commonly used for elimination leading to the alpha, beta-unsaturated lactone and the results provide practical guidance in choosing elimination conditions.

[Studies on retinoids. IV. Design, synthesis and structure-activity relationships of di-t-butylphenyl compounds].

Retinoic acid and its analogues play important roles in modulating cell growth, differentiation, immunity and apoptosis. Clinically they are used for cancer chemoprevention and chemotherapy. Based upon the moiety of 3,5-di-t-butyl-4-hydroxy phenyl ring, a series of substituted aromatic amide, ester and chalcones were designed and synthesized, which mimic the molecular shape, size, and spacial disposition of functional groups of retinoic acid. The general structure is as follows: [formula: see text] where R stands for hydrogen atom or methyl group, Y is the linkage -CONH-, -NHCO-, -COO-, -COCH = CH-, or a member of a heterocycle, X represents various substituents at different positions. The SAR indicates that the presence of hydrophobic group(s) at one end of the molecule, and a carboxyl group at the other end, and a conjugative system of molecule are necessary and full prerequisite for exhibiting activity. Loss of any one factor of them will abolish the activity. Being obligatory for anti-oxidative effect, the phenolic hydroxy group does not convey biological activity, because after methylation of the hydroxy group the compound increases the differentiation-inducing activity and loses the anti-oxidative effect, indicating that there is no correlation between the two activities. With a stable conformation of two phenyl rings with cis-conformation N-methylated acyl amide (No. 30) features in bent shape of the molecule, instead of an extended conformer, which is taken by the non-N-methylated partner and all-trans retinoic acid. A bent conformer of No. 30 accounts for the inactivity. In this paper compounds No. 4f, 4g, 5a, 7, 13, 32, 37, and 38 exhibited significant activity among them 4-[3-(3, 5-di-t-4-methoxyphenyl)-3-oxo-1-propenyl] benzoic acid (No. 38) showed high activity comparable to that of retinoic acid. The pharmacological action of No. 38 is under investigation.

[Differentiation of B16 melanoma cells induced by ginsenoside RH2].

The effect of ginsenoside Rh2, a constituent isolated from Panax ginseng C. A. Meyer, on the growth of tumor cells in vitro was investigated. The results showed that Rh2 inhibited the growth of B16 cells at the concentration of 10 micrograms.ml-1 (IC50: 4.1 micrograms.ml-1). Rh2 was found to significantly induce the activity of differentiation of B16 cells at the concentration of 10 micrograms.ml-1 in vitro. The melanin synthesis of Rh2 in treated B16 cells was increased. Morphologically, the Rh2 induced B16 cells turned to be epithelioid cells. B16 cells became dendrite shaped morphologically at higher concentration of Rh2. Flow cytometry demonstrated that the B16 cells treated with Rh2 were blocked at G1 phase.

Antifibrin monoclonal antibodies for the detection of venous thrombosis.

In order to specifically detect the localization of thrombus in vivo, we have recently developed two monoclonal antibodies (SZ-58, SZ-63) which can specifically bind to cross-linked fibrin. The binding rates of the two monoclonal antibodies (MoAbs) to human plasma clots in vitro were 46.4 +/- 2.3% for 125I-SZ-58, 50.1 +/- 1.7% for 125I-SZ-63 and 3.4 +/- 1.6% for 125I-SZ-53 (control, MoAb against TM). It was shown that both SZ-58 and SZ-63 possess properties of inhibiting the polymerization of fibrin, and SZ-58 could also inhibit the aggregation of platelets induced by ADP. These characteristics make the two MoAbs suitable in the detection of thrombus in vivo. According to the cross reaction tests, thrombi in the jugular veins and carotid arteries in rabbits were made. After injection of the 125I-labeled MoAbs (100,000 cpm/ml of blood), the thrombi and the blood were taken and weighed at various time intervals and radioactivities were measured by an autogamma counter. The ratios of thrombus to blood radioactivity (T/B) of thrombi in jugular veins were 3.0, 5.6 and 3.0 for 125I-SZ-58, 1.5, 3.0 and 5.2 for 125I-SZ-63 and 1.2, 1.0 and 0.7 for control (125I-SZ-53) at the 3rd, 12th and 24th hour after the injection of the radiolabled MoAbs, while the radioactivities of arterial thrombi were almost the same as that in blood after the injection of the two radiotracers. Therefore, it can be concluded that both SZ-58 and SZ-63 can be used in venous thrombus imaging in vivo and the optimal times of imaging are at the 12th hour for SZ-58, 24th hour for SZ-63 after the injection of the radiolabled MoAbs.

[Induction of apoptosis by harringtonine and homoharringtonine in HL-60 cells].

Harringtonine (HT) and homoharringtonine (HHT) are two alkaloids isolated from the bark of the evergreen tree Cephalotaxus hainanensis Li in the 1970s. They were found to have activity against murine leukemia, Lewis lung carcinoma and B16 melanoma, and used as anti-leukemia drugs clinically. Apoptosis is an active process of programmed cell suicide and now is believed to be an important target for tumor chemotherapy. In this report, the apoptosis inducing effect of HT and HHT in HL-60 cells were observed. The experiments demonstrated that 2 x 10(-7) mol.L-1 of HT and 10(-7) mol.L-1 of HHT could induce apoptosis in HL-60 cells when the cells were exposed to HT and HHT for 4 h. In agarose gel electrophoresis, DNA extracted from HL-60 cells treated with HT and HHT showed a typical internucleosomal DNA degradation, i.e., DNA ladder and parallel morphological changes as nuclear chromosome segmentation and condensation as well as cytoplasma vacuolation. This effect of HT and HHT was shown to appear in a concentration- and time-dependent manner. The efficacy of HT and HHT in inducing apoptosis of HL-60 cells was found to parallel with their cytotoxic activity in HL-60 cells. These results suggest that the mechanism of antitumor action of HT and HHT is related to their apoptosis inducing activity.

A deficiency of vitamin B6 is a plausible molecular basis of the retinopathy of patients with diabetes mellitus.

Eighteen patients with diabetes mellitus, some of whom had variously retinopathy, pregnancy, and the carpal tunnel syndrome, and were variously treated with steroids and vitamin B6, have been overviewed for periods of 8 months to 28 years. We have established an association of a deficiency of vitamin B6 with diabetes by monitoring the specific activity of the erythrocyte glutamic oxaloacetic transaminase and again by the association with the carpal tunnel syndrome (C.T.S.). It has been known for a decade that C.T.S. is caused by a B6 deficiency. The absence of retinopathy in vitamin B6-treated diabetic patients over periods of 8 months - 28 years appears monumental. These observations are like discovery and constitute a basis for a new protocol to establish the apparent relationship of a deficiency of vitamin B6 as a molecular cause of diabetic neuropathy. Blindness and vision are so important that the strength or weakness of the observations are not important; the conduct of a new protocol is important.

Improved methodology to assay carnitine and levels of free and total carnitine in human plasma.

Carnitine, once known as vitamin Bt, is intrinsic to human tissue and is biochemically established as being acylated with fatty acids by Acyl-CoA to give Acyl-carnitines which then are transported to the inner mitochondrial membrane by a translocase. Carnitine is of increasing clinical interest and importance, and endomyocardial deficiencies of carnitine have been reported for patients in heart failure. Consequently, a reproducible and accurate analysis of human tissue specimens for levels of free carnitine and Acyl-carnitine to guide and to support continuing clinical studies of disease states is needed. We have devised an analytical method which utilizes 5,5'-dithiobis-2-nitro-benzoate and demonstrated recovery, reproducibility and precision. Hydrolysis of a specimen at 90 degrees C for 15 min, and control of pH below 6.0 are critical steps. The mean levels of free carnitine and total carnitine in 17 ordinary subjects were 50.6 +/- 9.7 nmol./ml and 62.6 +/- 11.7 nmol./ml. respectively.

Coenzyme Q10 increases T4/T8 ratios of lymphocytes in ordinary subjects and relevance to patients having the AIDS related complex.

Coenzyme Q10 (CoQ10) is indispensable to biochemical mechanisms of bioenergetics, and it has a non-specific role as an antioxidant. CoQ10 has shown a hematological activity for the human and has shown an influence on the host defense system. The T4/T8 ratios of lymphocytes are known to be low in patients with AIDS, ARC and malignancies. Our two patients with ARC have survived four-five years without any symptoms of adenopathy or infection on continuous treatment with CoQ10. We have newly found that 14 ordinary subjects responded to CoQ10 by increases in the T4/T8 ratios and an increase in blood levels of CoQ10; both by p less than 0.001. This knowledge and survival of two ARC patients for four-five years on CoQ10 without symptoms, and new data on increasing ratios of T4/T8 lymphocytes in the human by treatment with CoQ10 constitute a rationale for new double blind clinical trials on treating patients with AIDS, ARC and diverse malignancies with CoQ10.

Lovastatin decreases coenzyme Q levels in rats.

Lovastatin is used for the treatment of hypercholesterolemia. It functions by inhibiting the enzyme, 3-hydroxy-3-methylglutaryl-coenzyme A reductase (EC 1.1.1.34), that is required for the conversion of 3-hydroxy-3-methylglutaryl-coenzyme A to mevalonic acid. Since biosynthesis of both cholesterol and coenzyme Q (CoQ) requires mevalonic acid as a precursor, it was considered that lovastatin therapy would also result in a lowering of cellular CoQ levels. This study was conducted to determine whether lovastatin treatment does decrease CoQ levels and whether such decreases can be prevented by CoQ supplementation. Forty-five adult male Holtzman rats were randomly assigned to one of three treatment groups. Controls were fed ground laboratory rat chow ad libitum. The other two groups were fed ground laboratory rat chow containing 400 mg of lovastatin per kg of diet ad libitum. One of the lovastatin-fed groups received CoQ10 (15 mg per kg of body weight) daily via stomach intubation. After 4 weeks, samples of heart, liver, and blood were analyzed for CoQ concentrations. Results indicated that CoQ concentrations in all tissues analyzed were decreased in lovastatin-treated rats. Lovastatin-treated animals that were supplemented with CoQ10 had blood, heart, and liver CoQ10 concentrations that approximated or exceeded those of control animals. It is concluded that lovastatin does indeed lower tissue concentrations of CoQ and that a return to normal can be achieved by supplementation with CoQ.

Lovastatin decreases coenzyme Q levels in humans.

Lovastatin is clinically used to treat patients with hypercholesterolemia and successfully lowers cholesterol levels. The mechanism of action of lovastatin is inhibition of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, an enzyme involved in the biosynthesis of cholesterol from acetyl-CoA. Inhibition of this enzyme could also inhibit the intrinsic biosynthesis of coenzyme Q10 (CoQ10), but there have not been definitive data on whether lovastatin reduces levels of CoQ10 as it does cholesterol. The clinical use of lovastatin is to reduce a risk of cardiac disease, and if lovastatin were to reduce levels of CoQ10, this reduction would constitute a new risk of cardiac disease, since it is established that CoQ10 is indispensable for cardiac function. We have conducted three related protocols to determine whether lovastatin does indeed inhibit the biosynthesis of CoQ10. One protocol was done on rats, and is reported in the preceding paper [Willis, R. A., Folkers, K., Tucker, J. L., Ye, C.-Q., Xia, L.-J. & Tamagawa, H. (1990) Proc. Natl. Acad. Sci. USA 87, 8928-8930]. The other two protocols are reported here. One involved patients in a hospital, and the other involved a volunteer who permitted extraordinary monitoring of CoQ10 and cholesterol levels and cardiac function. All data from the three protocols revealed that lovastatin does indeed lower levels of CoQ10. The five hospitalized patients, 43-72 years old, revealed increased cardiac disease from lovastatin, which was life-threatening for patients having class IV cardiomyopathy before lovastatin or after taking lovastatin. Oral administration of CoQ10 increased blood levels of CoQ10 and was generally accompanied by an improvement in cardiac function. Although a successful drug, lovastatin does have side effects, particularly including liver dysfunction, which presumably can be caused by the lovastatin-induced deficiency of CoQ10.

Ultrastructure of fresh and frozen-thawed spermatozoa of high and low fertility lines of chickens.

Level of damage caused by freezing and thawing to four spermatozoal organelles (individual mitochondrion, midpiece, nucleus, and perforatorium) and the relationships of the integrity of these organelles in fresh and frozen-thawed semen with fertility were examined. Semen sample from 10th generation males of a line of chickens selected for increased duration of fertility of frozen-thawed semen and the corresponding randombred control line were used. In both the selected and control lines, the freeze-thaw process caused significant (P less than .05) detrimental damage to the ultrastructure of the mitochondria, midpiece, and perforatorium but not to the nucleus. Types of damage were identical in both lines. Granulated nuclei were observed in both frozen-thawed and freshly ejaculated spermatozoa and were referred to as a nuclear defect. This nuclear defect was associated with reduced fertility, the effect being more severe with frozen-thawed semen. Where the incidence of the nuclear defect was greater than 2% in frozen-thawed semen, fertility was found to be very low or nil regardless of the degree of structural integrity of the mitochondria, midpiece and perforatorium. Highly significant (P less than .01) positive correlation coefficients were observed for percentage fertility 2 to 8 days postinsemination and duration of fertility in days with percentages of normal mitochondria (.80 and .92), midpiece (.79 and .87), nucleus (.86 and .94), and perforatorium (.84 and .97) for fresh semen. With frozen-thawed semen, the positive correlation coefficients were significant (P less than .05) for midpiece (.64 and .69) and nucleus (.63 and .71) and nonsignificant for mitochondria (.52 and .50) and perforatium (.20 and .30).(ABSTRACT TRUNCATED AT 250 WORDS)